It is often desired to take advantage of desirable properties of two or more unlike polymers, or of a polymer and a metal foil in manufacturing sheets or films to be used for coextrusion of two molten polymer streams in contact with each other to form a two-layer film. Unfortunately, however, two unlike polymers with unique desirable properties often fail to adhere to each other when the coextruded film cools. So as to obtain a strong bond between two unlike materials, a third composition is extruded between the two films. This third composition must have the ability to adhere to both of the other films and withstand the stresses to which the laminated structure is subjected when put to use. It is often necessary to formulate the bonding composition so as to meet the adhesion requirements of each laminated structure, as strong adhesion to several different types of films is difficult to achieve in a single composition.